Magnum engine misshapes..,

My 98 3/4 ton 5.9 gas was steaming mad today...
151k on the clock.
Driving to work I thought I smelled what seemed like wires burning???... Only one stop off the freeway and was idling a little rough... Got to work and smell seemed still there but faint..
Truck sat for five hours and I start it and take it up to 2k and hold for a few seconds and noticed a cloud of what looked like white smoke... I shut it off and kind of thoughtful.? Then I started again and let it run and it's puffing white smoke and I'm like well head gasket blown...
Of course I try to drive it home and hit the freeway and I'm really not having any problems with it. Not overheating and before I left I left and there was no water in the oil... I got home and no water in the oil and not see any dead cloud smoke or steam...
This ever happened to anybody else and it not be a major problem to fix? As far as I know I'm in for taking the heads off...
Thank you for everybody's time and experience..